Coordinate Input Apparatus and Control Method Thereof, Coordinate Input Pointing Tool, and Program

1. A coordinate input apparatus which calculates position coordinates of a coordinate input pointing tool with respect to a coordinate input surface, comprising: calculation means for calculating the position coordinates of the coordinate input pointing tool; change means for changing the position coordinates by multiplying the position coordinates by a predetermined coefficient that is obtained on the basis of a coordinate with a vertical direction axis with respect to the coordinate input surface, and that is related to a distance between the coordinate input surface and the coordinate input pointing tool; and output means for outputting the position coordinates changed by said change means.

2. The apparatus according to claim 1 , further comprising interpolation means for interpolating the position coordinates changed by said change means.

3. A control method of a coordinate input apparatus which calculates position coordinates of a coordinate input pointing tool with respect to a coordinate input surface, comprising: a calculation step of calculating the position coordinates of the coordinate input pointing tool; a change step of changing the position coordinates by multiplying the position coordinates by a predetermined coefficient that is obtained on the basis of a coordinate with a vertical direction axis with respect to the coordinate input suface, and that is related to a distance between the coordinate input, surface and the coordinate input pointing tool; and an input step of inputting the position coordinates changed in said change step.

4. A computer program stored in a memory which causes a computer to control a coordinate input apparatus which calculates position coordinates of a coordinate input pointing tool with respect to a coordinate input surface, comprising: program code for a calculation step of calculating the position coordinates of the coordinate input pointing tool; program code for a change step of changing the position coordinates by multiplying the position coordinates by a predetermined coefficient that is obtained on the basis of a coordinate with a vertical direction axis with respect to the coordinate input surface, and that is related to a distance between the coordinate input surface and the coordinate input pointing tool; and program code for an output step of outputting the position coordinates changed in the change step.